Allogeneic stem cell transplantation is a potentially curative treatment for patients with many hematologic malignancies (e.g. leukemia, lymphoma, and myeloma with high risk of relapse). This process requires a suitable donor. The best case scenario involves an Human Leukocyte Antigen (HLA) matched sibling donor. However, this type of donor is not always available. Donor registries can provide another source for matched unrelated donors, but this may take valuable time delaying treatment for the transplant recipient. Donor availability remains a significant barrier to the use of allogeneic (from a donor) stem cell transplant. This issue disproportionately affects patients of minority backgrounds. Novel strategies to improve outcomes using alternative donors are desperately needed.